Maybe he was thinking legacy, or maybe he was just trying to restore the country’s faith in jurisprudence over politics. Whatever the motivation, Supreme Court Chief Justice John Roberts provided the crucial fifth vote last June to uphold President Obama’s landmark health care reform law.

Not one Republican lawmaker voted for Obamacare. But Roberts, who was nominated to the high court by Republican President George W. Bush, found a way to back the law’s underlying premise that all Americans must have health insurance. It fell under Congress’s right to tax, he argued.

Maybe he was thinking about New Jersey’s need for federal dollars after a crushing natural disaster, or maybe he was just trying to strengthen his reelection prospects in a blue state. But in November, Republican Governor Chris Christie praised Obama’s “outstanding” leadership after Hurricane Sandy tore apart the Jersey shoreline. Christie’s unexpectedly kind words — and the photo of him with the president just days before the election — made headlines and rocked Mitt Romney’s world. It shouted cooperation instead of division as usual.

The left praised Roberts and Christie; the right vilified both.

But how about people in the middle, those 3 to 4 percent of voters who decide presidential elections? Perhaps they saw a Supreme Court justice and a governor who set aside personal ideology to reach for rare common ground. At a minimum, Roberts and Christie pulled off a surprise. They walked away from the double-down, no-surrender formula we have come to expect from partisans at either extreme. Then, they took the partisan wrath that went with it.

There was personal gain, to be sure, in the form of flattering assessments from liberals. But there was also a downside. Where liberals saw high-minded principle, conservatives saw crude political calculation.

It’s no accident that these two dramatic gestures of bipartisanship came from somewhere other than Congress. Because of the way congressional districts are created, there is little incentive to compromise in the House of Representatives. According to Nate Silver, The New York Times’s numbers guru, only 35 Congressional districts now qualify as “swing” — one-third of what there were 20 years ago. As a result, writes Silver, “most members of the House now come from hyperpartisan districts in which they are under essentially no threat of losing their seats to the other party.”

The contempt from both parties for supporting the opposing viewpoint carries over to the Senate. Just ask Senator Joseph Lieberman of Connecticut, who leaves office, as The New York Times describes it, “talking about how much people have hated him.”

Lieberman went against his party when he voted for war with Iraq and stuck with that position long after it became anathema to Democrats. After he lost his Democratic state primary and won reelection to the Senate as an independent, Lieberman further enraged Democrats by backing Republican John McCain in 2008 and by helping kill the public option in Obama’s health care bill.

“I’m not saying I was always right. I’ll leave that to God and history,” he told the Times. “But I believe I was doing what I thought was right and people didn’t just disagree with me. There was hatred.”

Lieberman now calls partisan fighting “a cancer that’s eating at our politics.” He has certainly been whiplashed by it. As Al Gore’s running mate in 2000, Lieberman could have been the first Jewish vice president, if the Supreme Court hadn’t split along ideological lines to award the presidency to George W. Bush.

Liberals still fume over that decision. Yet imagine their fury if a liberal soldier on the current court broke ranks as dramatically as Roberts did. Or if a Democratic governor had had something good to say about George W. Bush.

When Democrats or Republicans call for bipartisanship, they don’t think of reaching across to the other side. They think of the other side reaching across to theirs.

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